A facial recognition system is a computer application that automatically identifies or verifies a person from an image or a video. Face recognition in unconstrained images is at the forefront of the algorithmic perception revolution. The social and cultural implications and advantages of face recognition technologies are far reaching. Yet the current performance gap in this domain between machines and the human visual system precludes realization of these advantages.
Face recognition error rates have decreased over the last twenty years by three orders of magnitude when recognizing frontal faces in still images taken in consistently controlled (constrained) environments. Applications include border-control and smart biometric identification. However, these systems can be sensitive to various factors, such as lighting, expression, occlusion, and aging. The performance of these systems can substantially deteriorate when attempting to recognize people in unconstrained settings.